NEW YORK (TheStreet) -- Apple (AAPL) may be Monday's big newsmaker with its Worldwide Developer Conference. But traders on StockTwits.com aren't waiting for Tim Cook and Co. to get started. Instead, they're watching announcements from small drug companies on medication trials and tuning in to rumors about big pharma buyouts.

Drug companies Ariad Pharmaceuticals (ARIA), MannKind (MNKD), NPS Pharmaceuticals (NPSP) and Pharmacyclics (PCYC) were the top trending tickers on StockTwits.com Monday morning. They were joined on the trending bar of the dozen most discussed stocks by two biotech ETFs, iShares Nasdaq Biotechnology (IBB) and SPDR S&P Biotech (XBI).

Apple made the list too, due to hype over what management could reveal about the company's product pipeline and plans for Beats Electronics. But many on StockTwits.com said that excitement was misplaced. Apple, they noted, has a history of disappointing WWDC expectations. The stock has declined after eleven of the past conferences.

Investors on StockTwits were most interested in Ariad Pharmaceuticals. The company topped the StockTwits trending ticker bar with news that a drug to treat certain types of gastrointestinal tumors had positive results in early Phase II clinical trials. The FDA is lifting a partial ban that had restricted the company's ability to enroll new human test subjects.

Afrezza is pending FDA-approval and was overwhelmingly recommended by an FDA subcommittee earlier this year, despite concerns about lung complications with the drug. Investors believe that the drug could take over the $45 billion diabetes-management market, as many diabetics would prefer a treatment that doesn't involve daily shots. Sentiment on the stock is 97% bullish, according to StockTwits analytics.

$MNKD added few more. Like the way she's holding. Expecting a strong action EOD

NPS Pharmaceuticals shares were up nearly 15% by 11 a.m. after a report in the Financial Times that Shire (SHPG) is considering acquiring the company. And investors on StockTwits.com said shares should could climb higher than the $35.61 if rumors prove true that Shire secured a $5 billion credit facility to make a bid for the drug company, which focuses on treatments for people with rare disorders.

Pharmacyclics rose more than 2% after the company announced that its FDA-approved Imbruvica cancer drug boosted the survival rates of patients with leukemia or small lymphocytic lymphoma better than competing drugs. Patients who received the drug had a 78% reduction in the risk of cancer progression or death.

Sentiment on the stock was overwhelmingly bullish, with 89% of the crowd on StockTwits calling for gains, according to site analytics.

$PCYC This is a good stock to be in if you are not on a 1 - 2 day time horizon. Great data, FDA approved, sales ramping up.